About thetop boundary of Archean,we use the age of 2. 5 Ga, which was determined by the international Committee of Stratigraphy.是什么意思_About thetop boundary of Archean,we use the age of 2. 5 Ga, which was determined by the international Committee of Stratigraphy.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句